1. Field of the Invention
The present invention relates generally to a method of depositing an electrodepositable coating composition onto at least a portion of a substrate through the use of a plurality of liquid streams.
2. Background Information
Utilization of a flow coating process to deposit an electrodepositable coating composition onto a substrate is well known in the art. In these processes, an electrodepositable coating composition, which is also referred to as an e-coat or electrodeposition coating, is deposited onto a conductive substrate via an electrical process.
In general, the flow coating process can be seen as an electrical circuit when an electrical current is applied to the system. In this electrical circuit, the electrodepositable coating composition has a cationic or anionic charge while the surface of the substrate, which is to be coated, has a charge that is opposite to that of the electrodepositable coating composition (i.e., the surface may be anionic or cationic). During the coating process, a complete electrical circuit is created by a direct current rectifier thereby allowing the coating composition to deposit onto the oppositely charged surface of the substrate. However, in order to complete the electrical circuit, the conductive substrate is grounded or bonded to the rectifier through the use of a mechanical contact, such as a clip, which contacts or is connected to the substrate.
One shortcoming of using this mechanical contact, however, is that the point or area of contact (“contact point”) will not be coated with the electrodepositable coating composition since it is covered by the mechanical contact and, therefore, the electrodepositable coating composition is not applied to that area. Since the contact point is not coated with the electrodepositable coating composition, it not only detracts from the visual appearance of the substrate (i.e., the substrate is not uniformly coated with the coating composition), but the contact point can also be more susceptible to corrosion when compared to an area that has been coated with the electrodepositable coating composition.